3GPP, or the 3rd Generation Partnership Project, is a collaboration agreement that was established in Dec. 1998 between various organizations including: ETSI (Europe), ARIB/TTC (Japan), CCSA (China), ATIS (North America) and TTA (South Korea). The scope of 3GPP was to make a globally applicable third generation (3G) mobile phone system specification. Global System for Mobile Communications (GSM) is the most popular standard for mobile phones in the world. The 3GPP specifications are based on the evolution of the GSM specifications, now generally known as the UMTS (Universal Mobile Telecommunications System).
Unlicensed Mobile Access (UMA) lets wireless service providers merge cellular networks and IP-based wireless networks into one seamless service with one mobile device, one user interface, and a common set of network services for both voice and data. The UMA solution converges cellular networks with any IP-based wireless access network, such as IEEE 802.16 (WiMAX) networks, IEEE 802.20 Mobile Broadband Wireless Access (MBWA), Ultra Wideband (UWB) networks, 802.11 wireless fidelity (Wi-Fi) networks, and Bluetooth networks. UMA has recently been accepted into release 6 of the 3GPP standard as a General Access Network (GAN).
With UMA or GAN, subscribers may move between the cellular networks and IP-based wireless networks with seamless voice and data session continuity as transparently as they move between cells within the cellular network. Seamless in-call handover between the IP-based wireless network and cellular network ensures that the user's location and mobility do not affect the services delivered to the user. The subscriber experiences service, location, and mobility transparency. Services may be identical when connected over the IP-based wireless network or the cellular network.
UMA effectively creates a parallel radio access network, the UMA network (UMAN), which interfaces to the mobile core network using existing mobility-enabled, standard interfaces. The mobile core network remains unchanged. The common mobile core network makes it possible to deliver full service and operational transparency. The existing service provider Business Support Systems (BSS), service delivery systems, content services, regulatory compliance systems, and Operation Support Systems (OSS) can support the UMA network without change. Service enhancements and technology evolution of the mobile core network apply transparently to both the cellular access and UMA networks.
Typical wireless connections allow users via software clients to connect a wireless device to an access point associated with an alternate wireless network, in order to access a communication network such as the Internet. Generally, these software clients locally store parameters associated with alternate wireless networks available to the device, in order to provide the device with quick and open access when a user requests such access. Additionally, users of the device (and client) are able to add, delete, and/or modify the stored alternate wireless networks within the device. In some cases, these clients typically operate in two modes: (1) an automatic mode whereby the client scans available frequencies and automatically connects to available alternate wireless networks, and (2) a manual mode whereby the client provides a user with a list of alternate wireless networks and the user chooses a network. Generally, however, the client will connect to any available alternate wireless network.
As mentioned above, UMA networks typically provide voice communications. Unlike data connections, voice connections are sensitive to changes in connection speed, jitter, and other hindrances that negatively effect a connection. Therefore, it may not be ideal to invoke a connection to a voice communication network in a similar fashion to other types of communications. These and other problems exist with respect to wirelessly connecting to IP-based networks.